1. Field of the Invention
The present invention relates to an electron-emitting apparatus including an emitter section made of a dielectric material, a lower electrode disposed below the emitter section, and an upper electrode disposed above the emitter section.
2. Description of the Related Art
In the related art, an electron-emitting apparatus including an emitter section made of a dielectric material, a lower electrode (lower electrode layer) disposed below the emitter section, and an upper electrode (upper electrode layer) disposed above the emitter section and having numerous micro trough holes has been known. According to this type of electron-emitting apparatus, a high-voltage pulse is applied between the upper electrode and the lower electrode to reverse the polarization of the dielectric material and to thereby emit electrons through the micro through holes in the upper electrode (e.g., refer to Japanese Patent No. 3160213, claim 1, paragraphs 0016 to 0019, and FIGS. 2 and 3).
This type of apparatus is applicable to displays. For example, as shown in FIG. 22, an electro-emitting apparatus applied to a display includes a transparent plate 17, a collector electrode 18, and phosphors 19 opposite to upper electrodes 14. According to this electron-emitting apparatus, the phosphors 19 are irradiated with electrons emitted from an emitter section 13 through micro through holes (not shown) in the upper electrodes 14, and thereby generate light. The collector electrode 18 is provided to accelerate the emitted electrons, and a predetermined positive voltage Vc is constantly applied to the collector electrode 18.
A control for light emission by electron emission is performed by, for example, a scheme shown in FIG. 23. Specifically, from time t10 to time t20, the electro-emitting apparatus sets a drive voltage Vin between an upper electrode 14 and a lower electrode 12 (i.e., the potential difference between the lower and upper electrodes with respect to the potential of the lower electrode 12) at a particular negative value so as to reverse the orientation of dipoles (polarization reversal) in the emitter section 13 and to thereby supply electrons from the upper electrode 14 to the emitter section 13. The electrons are thereby accumulated mainly near the upper portion of the emitter section 13. At the time t20, the electron-emitting apparatus sets the drive voltage Vin at a predetermined positive value so as to reverse the polarization of the emitter section 13 for the second time. This polarization reversal allows the electrons accumulated near the upper portion of the emitter section 13 to travel in the upward direction due to Coulomb repulsion. As a result, the phosphor 19 is irradiated with electrons and thereby emits light. Subsequently, at a time t30, the electro-emitting apparatus sets the drive voltage Vin at the predetermined negative value again so as to resume the accumulation of the electrons, and, at a time t40, sets the drive voltage Vin at the predetermined positive value to allow the electrons to be emitted in the upward direction, thereby achieving light emission.